648643 has 4 divisors (see below), whose sum is σ = 671040. Its totient is φ = 626248.

The previous prime is 648631. The next prime is 648649. The reversal of 648643 is 346846.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 648643 - 2¹⁷ = 517571 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (648649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11155 + ... + 11212.

It is an arithmetic number, because the mean of its divisors is an integer number (167760).

2⁶⁴⁸⁶⁴³ is an apocalyptic number.

648643 is a deficient number, since it is larger than the sum of its proper divisors (22397).

648643 is a wasteful number, since it uses less digits than its factorization.

648643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22396.

The product of its digits is 13824, while the sum is 31.

The square root of 648643 is about 805.3837594588. The cubic root of 648643 is about 86.5635871785.

The spelling of 648643 in words is "six hundred forty-eight thousand, six hundred forty-three".